I Promise
by consultingpathologist
Summary: While serving as a nurse in France, Molly anxiously awaits news from Sherlock who is fighting on the front. WWI AU.
1. A Letter?

_**Inspired by an episode of The Crimson Field that had me in tears.**_

* * *

Molly rubbed at her bleary eyes before looking down at the watch on her wrist. She'd been awake for nearly twenty-four hours now. The large convoy from the front the night before had kept the makeshift hospital even busier than usual. Everyone had been working around the clock to get a handle on the most seriously wounded cases. She'd lost track of the number of amputations that had been done in the just the fast few hours alone. It was some of the worst injuries she had seen since arriving. But though her body was exhausted, more than anything she felt a sense of numbness settle in her bones.

She thought her training in nursing would have prepared her for this, but it hadn't, not completely. Nothing could have prepared anyone for the sights, sounds, and smells that she had experienced in her short time in France. The anguish on the injured soldiers' faces as they were brought down from the trucks, the cries due to nightmares that woke her from her slumber, the smell of burnt flesh that seemed to linger in the air, it was hard not to be overwhelmed. The older, more experienced nurses had told her that her body would adjust to the physical toll and that eventually she would learn how to distance herself from the emotional aspect of it. Perhaps the numb sensation meant that she was finally learning how not to let it consume her. It scared her that one could become used to such tragedy.

It wasn't all tragedy though. She had her close friend Mary with her which was like having a piece of home. She had grown close to the other doctors and nurses and enjoyed the camaraderie that they all shared. In this middle-of-nowhere, they had formed a small, tight knit community and spent down time joking around and sharing stories about life back in London. It helped to lighten the mood and escape the dreariness of their surroundings for a bit. She also enjoyed getting to know the soldiers as they recovered. Everyone had a story to tell.

Despite all gloom around her, she wouldn't have chosen to be anywhere else. Volunteering to serve in France had been the best decision she had made. She had felt rather useless back in England, dawdling her time away as she waited for news. Her skills were needed here.

A firm hand on her shoulder shook her out of her reverie.

"The tent. Go now. I'll cover for you," Mary's voice whispered into her ear. As she walked by, she turned briefly to give Molly a small smile before heading to fetch fresh bandages from the supply closet. Mary didn't even have to explain. Molly knew what it meant.

A letter had arrived.

The two had an agreement to tell each other the moment any news arrived. Good or bad. Long or short. They had both decided it was best to know right away.

Mary had gotten a letter from her husband John three days ago. He'd been in a close call while treating a man on the battlefield but had managed to walk away unscathed. Molly had held her normally composed friend as Mary's relief poured out in a flood of tears.

They had only been married for two weeks before John had to ship off to France. They had known it was coming and decided to marry quickly instead of waiting. It had been an extremely small affair with only Molly and Sherlock, their best friends, in attendance serving as witnesses. During the ceremony as she held Mary's bouquet, she caught Sherlock's eye and wondered if they might ever find themselves in the same position.

 _Sherlock_.

It had been two months since she'd heard from him and nearly six since she'd seen him back in England when he was last on leave. She spent her days in fear that she'd see him be brought to this very hospital, yet at the same time wanting more than anything to see him. As much as she wanted him to be safe from harm, she would also give anything to hold him in her arms again. It felt twisted but it was war. Nothing seemed to make sense.

At the first chance that the head Matron was busy with a patient, Molly quietly slipped out into the brisk night air and made her way across the camp. As she dodged people milling about outside, she braced herself for the news that awaited her. It could be anything and the unknown terrified her. The look Mary had given led her to believe it wasn't the sort of letter to worry about, but then again Mary had no way of knowing the message it contained. As long as she saw his scrawled handwriting on the envelope, it would be a good sign. Anything but the dreaded formal notice in bolded letters sent from the London head office which only signaled the worst news imaginable.

The area around the lodging tents was empty as everyone was busy working double shifts so Molly could breathe a little easier. She slipped inside the canvas flap and lit a small lantern. There was no letter waiting. Nothing on the bed, nor the small nightstand. She checked the ground and under the bed thinking it may have been blown off in a gust of wind but still nothing. Just as she was about to search Mary's side, her eye caught a flash of metal in the small mirror hanging above her bed.

Her heart stopped as she studied the reflection in the dim light and realized someone was standing behind her. The someone was dressed in uniform and had short dark curls that fell across his forehead as he removed his hat.

It couldn't be. Her exhaustion must have made her delusional. _And yet_.

The face in the mirror became clearer as he slowly walked towards her. A tender smile formed at the corners of his mouth.

"Molly," spoke the deep voice that she'd so longed to hear.

A guttural sob that had been caught deep in her chest finally escaped before she could control it. Slowly she turned around and as she laid eyes on him her knees buckled. Rushing over to her, he caught her by the shoulders and crushed her to his chest.

"Molly."

She couldn't stop the tears that flowed onto her cheeks if she wanted to. But she didn't want to.

He was here. He was safe.

Her two wishes had been granted. It was the best thing she could've asked for.

They clung to each other, both savoring the closeness of each other's bodies after so long apart.

Once the initial shock wore off, she pulled back to get a better look at him. Though he looked a little fatigued by his journey and everything else he'd been through, there was that same mischievous sparkle in his eyes. Bringing her hand to his face, she touched the smooth skin gently still not completely able to believe it was real.

"How?" was the only word she could formulate.

"Got a week's leave at the last minute and thought I might surprise you," he said as he reached for a strand of her hair that had fallen out of her cap.

"Well, you certainly did that." No wonder Mary had been unable to hide a smile, she'd been keeping a secret.

"I'm staying at a hotel in Boulogne. Perhaps you might find yourself available in the next few days."

"Oh?" she said playfully. "And just might we do with our time off?"

He leaned forward and she could feel his breath on her cheek as he spoke in her ear.

"I have a few ideas," his voice rumbled deep within his throat sending shivers down her spine.

As he lowered his lips onto hers, she knew that whatever doubts she had had about their relationship could be wiped clean away.

And the three words that he whispered into her ear were the final proof.


	2. A ring

_Months before the war…_

"Love is a dangerous-"

"Oh _please_ , Sherlock, not this speech again," Mary interrupted as she walked over to hand him a teacup.

The four of them had ended up stranded at Baker Street after the pouring rain put a damper on their dinner plans. Though the kitchen had been shockingly lacking in food (but full of other surprises), with the help of the landlady, Mrs. Hudson, they had managed to pull together a decent last-minute meal.

Despite the change in plans, it had not been an altogether unpleasant evening. In fact, Molly found it more enjoyable than a normal night out. The small flat was quite cozy with the fire roaring and the smells of cigarettes and old books added to the homey atmosphere. The rain could keep up all night, she didn't mind one bit.

She had only met him briefly a couple times before. Most of what she knew about him had come as secondhand information from Mary. Her best friend was dating his best friend and roommate John and from Mary's hints the relationship was taking a more serious turn. It had only been a matter of time before she found herself in the presence of Sherlock Holmes and given the ability to determine his character for herself.

And to her surprise, despite all the warnings, she found she quite liked him. Sure he was a bit obstinate, sarcastic, and prone to ill temper, but he was also fascinating to listen to, was some sort of genius, and also, judging from his cluttered flat, happened to share some of her interests in science and medicine. There was also the small fact that he was simply beautiful to look at-tall and slender with dark curly hair that softened angular features. He wasn't like any of the average blokes she'd known before. Being in his presence was a refreshing change.

She wanted to know more about this mysterious detective.

"What were you about to say?" she asked, blowing on her hot tea before taking a sip.

"Sherlock doesn't approve of Mary and I dating, or for that matter anyone _ever_ ," John answered rolling his eyes at his friend. Mary giggled and sat in her boyfriend's lap as if to show her defiance.

Sherlock scoffed from where he stood by the fireplace. "It's not that I disapprove, it's just that I find the whole idea of love a complete farce and destructive for thinking."

"How so?" Molly asked with growing curiosity.

He turned towards her and for the first time studied her with great interest. She had to keep herself from fidgeting under the directness of his gaze.

"It basically boils down to the release of a few chemicals in the brain preventing it from functioning properly and turning the person into a useless member of society," he said finally.

"Says someone who's never been in love before," Mary said with a laugh as she rested her head on John's shoulder.

"One day you'll feel differently, Sherlock," agreed John as wrapped his free arm around Mary's waist.

Sherlock grunted and turned back towards the fire.

"I know a bit about the science of it, but surely there's something more, something that can't quite be explained with logical theories. It's more complex than that. I mean love is something that people have been trying to understand since the beginning of time and here we are still trying to wrap our heads around it. Perhaps it's a subject better suited for the poets and writers to try to explain," Molly said as three pairs of eyes turned towards her. She shrugged casually and took another sip of her tea.

Sherlock looked a bit bewildered. "Science can explain anything."

"Yes, but it doesn't keep your bed warm at night. It doesn't kiss you before you leave the house in the morning and get you ready for the day. It doesn't explain the pain you feel when the other person is away and not at your side. It doesn't hold you close and let you cry on its shoulder."

He cleared his throat as he thought about her words. The jovial, teasing tone of the room had changed. She hadn't meant to, but she couldn't accept his simplified explanation without challenging it.

"Let's change the subject. It's too dreary for such serious talk," said Mary.

Molly knew she didn't mean just the weather outside, but the state of the world in general. Talk of a war was increasing every day. It was almost inevitable. The whole country at the moment was on edge, holding their loved ones close as they waited for the news. How many more nights together like this would they have?

She was determined to make the most of it.

"I see from your bookshelves that you enjoy biology and chemistry. I studied those in school-before switching nursing that is," she said cheerily, hoping to lighten up the mood.

The sparkle that appeared in his eyes let her know she'd hit on one of his favorite topics. "I'm a graduate chemist. Why did you leave it?"

She looked down at her lap and smoothed an imaginary wrinkle in her skirt. "My parents thought it wasn't practical for a woman. I switched to nursing so I could still study those subjects while doing something they would approve of. There's always a great demand for nurses and, well, with the way things are going that need will only grow."

When she looked up again, she was surprised to see that Sherlock was now sitting in the chair next to her. For the rest of the evening they continued to talk about their shared interests, not paying much attention to the wide-eyed looks and whispers from Mary and John, until the rain stopped and the last embers of the fire died out.

As the two women prepared to leave, Sherlock stood to help her into coat.

"Thank you for a pleasant evening, Ms. Hooper, I hope we will be able to continue this conversation in the future," he said with a genuine smile, causing Mary's jaw to drop.

"Please call me Molly," she replied, "And thank you, I would like that very much."

As the two of them stepped outside to fetch a cab, Mary was still shaking her head in amazement. "Well, I never…"

Molly couldn't help but be surprised herself after what she had heard about him, but she knew she was definitely looking forward to seeing more of this Sherlock Holmes.

* * *

"I bet I can beat you to the water," she said slipping off her shoes and sprinting away before waiting to hear his answer.

She barely heard his complaint about unfairness as she raced towards the ocean. The head start didn't help her much though because his long legs were able to reach her just at her feet hit the wet sand.

He wrapped his arms around her waist and carried her to the water where they ended up tumbling amongst the crashing waves that drowned out their laughter.

It felt so good to be carefree again. The shock of the cold saltwater made her come alive like she was waking from a long slumber. For these brief few moments, she refused to think about the war currently going on or the fact that Sherlock had to return to it.

Right now it was just the two of them on a windy day at the beach in the north of France.

For the past week, it had just the two of them in a hotel bed finally satisfying their physical desire and doing little else.

Later as they sat on the beach wrapped in towels covering their soaking under clothes, Sherlock's face turned serious for the first time since he had arrived.

"Molly-"

"Don't say it, Sherlock," she pleaded, "whatever it is let's just not think about it right now."

"I need to say it though. My time here is almost up."

She buried her face against his chest. This conversation had been coming she knew it. She just didn't want to think about it now.

He held her a moment before lifting her chin so his eyes could meet hers.

"There are no certainties when it comes to war. I can't be sure of making it through the day-"

"Sher-"

"-But..." he said with determination before pausing to brush his hand against her cheek. "But I am sure of one thing. Something I never thought I would ever say if I'm being honest, but that has changed since meeting you. I love you. I want to be with you. Always."

To say she was surprised by his words was an understatement. As much as she had hoped, she never thought it was really a possibility. She thought he was going to put an end to it to spare her further pain. How wrong she'd been.

He reached for his uniform that was lying in the sand and pulled something from one of the front shirt pockets.

"I've carried this with me since the day I left for France," he said opening his fingers and revealing a small diamond ring with a delicate gold band resting on his palm.

She couldn't help but gasp, "Sherlock…"

"You know what-John was right-as much as I hate to admit it. I didn't know that this could ever happen to me, I didn't want it to, but you've changed that for me and I'm glad you did. I wanted to ask you on the docks that day I left and I've regretted the fact that I didn't every day since," he paused to take a deep breath. "I didn't want you to have the burden of waiting for me so I decided to wait until after the war, but I've been nearly driving myself mad. I understand if the answer is no, but I just have to know one way or the other. Molly, will you marry me?"

The diamond glittered in the sunlight as he held it out to her.

She thought for moment before giving her answer. "Yes. Yes, I will…on one condition."

He looked at her in surprise. "Anything."

"You have to promise to return to me. I know that everything with war is uncertain, but you _must_ promise me."

He smiled tenderly. "I promise. I _will_ come home."

The ring slid onto her finger with ease. She wouid forever be able to look at it and remember this moment, his promise to her.

"Another thing…"

The sparkle of amusement returned to his eyes. "Oh?"

"You really must promise to write more letters. I can't deal with this endless waiting for months for news from you."

He laughed and wrapped his arms around her, drawing her close. "You have my word."

"I love you."

"I love you too, Molly Hooper."

They sat in silence and watched the waves until the sky turned dark.

* * *

The small diamond sparkled as she held it out in front of her. Though it had been a few days, it still caught her off guard. As soon as he had left, she removed it from her finger and put it on a chain that she wore under her uniform. It felt safer to have it tucked away while she was working. The coolness of the metal against her skin was a constant reminder of him. It wasn't just a symbol of her pledge to marry, it was also as much his promise as well to return home, to return to her.

"Well?" Mary asked as she walked by with a basket of freshly laundered sheets. "Are you going to tell me?"

Molly had planned on keeping it a secret, but no doubt the joy on her face was obvious to everyone around her. She reached under her shirt and pulled out the chain.

Mary let out a shriek and dropped the basket to hug her best friend. "I knew it. I could see it on his face that night he arrived."

"They're coming home. Both of them. I made him get John to promise as well."

Mary nodded a bit solemnly and Molly gave her friend another hug to prove it.

 _They would. They must._

* * *

The wait was long and not without its frustrations.

John was shot in the leg and brought to a hospital in Calais. Mary left to go be with her husband and though Molly understood, she couldn't help but miss her friend dearly. He was able to make a full recovery, but there would always be a slight limp in his walk to serve as a reminder of the havoc that the war had caused. So many were not as lucky.

Sherlock kept his promise to write more letters, but the post was not always reliable and often terribly late. The letters that did reach her were saved and read whenever she needed reassurance.

As the war wound down, the hospital closed and she returned to England to continue with her studies. The country slowly began to find its way back to normal, or as normal as it could be after the tragedy that it had survived.

And one day it was all over, though it had already been officially declared as such. For her it wasn't over until the day she stood at her locker in the hospital changing room. She heard a noise behind her and just as she had in a field in France she looked up and saw his face in the mirror, smiling with a twinkle in his eye.

She spun around and ran to him, leaping into his arms and not caring about the appropriateness of it one bit.

"You're back."

"I promised, didn't I?"

That was the end of it for her, as well as the beginning.


End file.
